Apparatus for processing signal in monitor

ABSTRACT

A display apparatus, and more particularly, a display apparatus capable of indicating a picture-in-picture (PIP) function on a color display tube (CDT) monitor, is provided. The display apparatus includes a signal dispensing unit for dispensing an output signal output from a personal computer (PC) in the form of an analog or digital signal and outputting the same, a signal processing unit for performing PIP signal processing enabling one of a digital PC signal generated by the signal dispensing unit and a decoded TV/video signal input from an outside source to be displayed on a main screen and the other to be displayed on one or more sub-screens, and for processing the TV/video signal to be displayed alone on the main screen, an outputting unit for outputting an analog PC signal generated from the signal dispensing unit in response to a control signal for displaying only the PC signal, and outputting an output signal of the signal processing unit in response to a control signal for displaying the PIP and TV/video signals, and a monitor for amplifying the signal output from the outputting unit to be displayed. According to the display apparatus, the PIP function can be realized, and also, a signal of high definition can be displayed on the CDT monitor.

CLAIM OF PRIORITY

[0001] This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application for AN APPARATUS FOR PROCESSING SIGNAL OF MONITOR earlier filed in the Korean Industrial Property Office on Jun. 30, 2001 and there duly assigned Ser. No. 2001-38811.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a display apparatus, and more particularly, to a display apparatus capable of indicating a picture-in-picture (PIP) function on a color display tube (CDT) monitor.

[0004] 2. Description of the Related Art

[0005] With a jump to a higher level of information society, multimedia systems have rapidly come into wide use. Accordingly, the importance of display devices functioning as a bridge between human beings and electronic devices has increased.

[0006] Analog signals have been generally used when displaying a signal from a personal computer (PC) or television/video through a CDT monitor system. As shown in FIG. 1, a signal from a PC 10 is amplified by an amplification unit 11 and is displayed on a CDT 12 monitor such as a cathode-ray tube. On the other hand, digital data must be used when a signal from the PC or television/video is displayed through a liquid crystal display (LCD) monitor system.

[0007] In order to realize the PIP (picture-in-picture) function of indicating at least one sub-screen together with one main screen at the same time, as an optional function of a monitor, a signal from a PC or television/video must undergo a digital signal process. Therefore, the PIP function can be more easily realized in the LCD monitor than in the CDT monitor. To realize the PIP function in the CDT monitor, a scaler integrated circuit (IC) that is used in the LCD monitor is needed. However, when the scaler IC is used, a signal is displayed on the CDT screen after being converted into a digital signal, processed with a PIP process in the scaler IC, and then converted back into an analog signal. During these processes, screen image quality may be degraded.

SUMMARY OF THE INVENTION

[0008] It is therefore an object of the present invention to provide an apparatus for processing signals in a monitor so that an image of high definition is displayed without any degradation of image quality when the PIP function is realized in the CDT monitor.

[0009] It is another object to have an apparatus for processing signals in a monitor for the picture-in-picture function that is easy to manufacture.

[0010] It is another object to have an apparatus for processing signals in a monitor for the picture-in-picture function that is inexpensive to manufacture.

[0011] Accordingly, the above and other objects are achieved by an apparatus for processing a signal. It is preferable that the apparatus includes a signal dispensing unit for dispensing an output signal output from a personal computer in the form of an analog or digital signal and outputting the same, a signal processing unit for performing picture-in-picture signal processing enabling one of a digital personal computer signal generated by the signal dispensing unit and a decoded television or video signal input from an outside source to be displayed on a main screen and the other to be displayed on one or more sub-screens, and for processing the television or video signal to be displayed alone on the main screen, an outputting unit for outputting an analog personal computer signal generated from the signal dispensing unit in response to a control signal for displaying only the person computer signal, and outputting an output signal of the signal processing unit in response to a control signal for displaying the picture-in-picture and television or video signals, and a monitor for amplifying the signal output from the outputting unit to be displayed.

[0012] It is preferable that the apparatus further includes a signal conversion unit for converting the picture-in-picture signal output from the signal processing unit into an analog signal before a signal is output from the outputting unit. The signal processing unit includes a decoding unit for converting the television or video signal into a digital signal and decoding the same, a scan rate conversion unit for converting a scan rate of the decoded television or video signal, and a signal processing unit for performing a picture-in-picture signal process on the television or video signal whose scan rate is converted and the digital personal computer signal, so that one of the television or video and the digital personal computer signal is displayed on the main screen and the other of the television or video and the digital personal computer signal is displayed on the plurality of sub-screens, or for processing the television or video signal to be displayed alone on the main screen.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:

[0014]FIG. 1 is a block diagram of an apparatus for processing signals in an earlier color display tube (CDT) monitor; and

[0015]FIG. 2 is a block diagram of an apparatus for processing signals in a monitor according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0016] Turning now to the drawings, referring to FIG. 2, the apparatus includes an ADC (analog to digital converter) 21 for converting an analog signal output from a personal computer 20 into a digital signal, a decoding unit 23 for converting a signal from a television or video 22 into a digital signal and decoding the same, a scan rate conversion unit 24 for changing a scan rate of the decoded signal from the television or video 22, a signal processing unit 25 for performing the picture-in-picture (PIP) function of displaying one of the personal computer (PC) 20 signal output from the ADC 21 and the television or video 22 signal output from the scan rate conversion unit 24 on the main screen and displaying the other on a plurality of sub-screens, or processing the television or video signal to be displayed, a DAC (digital to analog converter) 26 for converting an output signal generated from the signal processing unit 25 into an analog signal, an outputting (switching) unit 27 for outputting the analog signal output from the personal computer 20 when only the personal computer 20 signal is displayed and outputting a signal output from the DAC 26 when both the PC 20 signal and the television or video 22 signal are displayed using the picture-in-picture function, an amplifying unit 28 for amplifying a signal output from the outputting unit 27, and a color display tube 29 for displaying the amplified signal.

[0017] In FIG. 2, the apparatus for processing a signal in the monitor is operated largely in three modes including displaying a signal from the PC 20 (1st mode), displaying a signal from the television or video (TV/video) (2nd mode); and displaying two or more signals at the same time, i.e., picture-in-picture function (3rd mode). The television signal can be defined as broadcast video signals used to display an image that are for example transmitted through the air or through mediums such as conducting wire, fiber optics, or other mediums. The video signal can be defined as any possible signal that can be used to display an image and may include for example non-broadcast video signals such as from a video cassette recorder, digital versatile disc, video compact disc, and other media that can be used to generate a video image. The television or video signal can for example be originally in formats such as NTSC (National Television Standards Committee), SECAM (Sequential Color and Memory System), PAL (Phase Alternating Line), or other formats. The signal from the personal computer 20 can be for example in a VGA (Video Graphics Array) mode format or other modes with higher resolution (i. e., SVGA for super video graphics array, XGA for extended graphics array, etc.). The signals above have varying constraints such as frequencies and resolutions.

[0018] In the first mode, the color display tube 29 displays a signal from the personal computer 20 without modification. A signal from the personal computer 20 is selected by inputting an outputting (switching) control signal to the outputting unit 27. The selected signal from the personal computer 20 is amplified by the amplifying unit 28 and output to the color display tube 29. A signal dispensing unit 40 for dispensing a pure analog signal output from the personal computer 20 and a digital signal passing through the ADC 21 is included in the apparatus. In the first mode, the analog signal from the personal computer 20 is output from the signal dispensing unit 40.

[0019] In the second mode, a signal from the television or video unit 22 is converted into a digital signal and decoded in the decoding unit 23. For smoothly processing a signal, a scan rate of the decoded signal from the television or video is changed by the scan rate conversion unit 24. A horizontal frequency of the personal computer 20 is 30˜85 kHz (17″, 19″ diagonal measurement of display screen) and that of the television or video 22 is 15.7 kHz (kilohertz) and thus, an error due to a large difference between the horizontal frequencies maybe made during signal processing. This problem can be solved by changing the scan rate of a signal generated from the television or video 22. A television or video 22 signal having a horizontal frequency of 15.7 kHz is changed to have a horizontal frequency of 31.4 kHz when passing through the scan rate conversion unit 24. The television or video 22 signal whose scan rate is changed is scaled in the signal processing unit 25 to be displayed on the CDT 29. The scaled television or video 22 signal passes through the DAC 26 and is then converted into an analog signal. A signal output from the DAC 26 is selected by inputting an outputting control signal to the outputting unit 27. The selected signal from the PC 20 is amplified in the amplifying unit 28 and output to the CDT 29.

[0020] In the third mode, at least two signals are displayed (PIP function) at the same time, i.e., the signals of the PC 20 and the TV/video 22 are displayed at the same time. According to one embodiment of the third mode, a digital signal output by the PC 20 is output from the signal dispensing unit 40 to the signal processing unit 25. The signal from the TV/video 22 passes through the decoding unit 23 and the scan rate conversion unit 24 and is output to the signal processing unit 25. In this mode, the signal processing unit 25 selects a main screen and sub-screens, processes a signal to correspond to a selected screen and processes a scaling for displaying the signal. As another embodiment, to realize the PIP function, a signal from the PC 20 and a signal from the TV/video are displayed, one on the main screen and the other on a sub-screen. A PIP signal generated from the signal processing unit 25 is converted into an analog signal in the DAC 26. In this mode, a signal output from the DAC 26 is selected by inputting an outputting control signal to the outputting unit 27. The selected signal from the PC 20 is amplified in the amplifying unit 28 and output to the CDT 29. The function of the outputting unit 27 is the same in the second and third modes, i.e., it is controlled to switch an output signal of the DAC 26. However, the function of the DAC 26 is not the same. That is, the DAC 26 outputs the scaled signal of the PC 20 to be displayed in the second mode, whereas it outputs signals from the PC 20 and the TV/video 22, which are PIP processed, to be displayed in the third mode.

[0021] According to the above-described apparatus, a pure signal from the PC 20, a signal from the TV/video 22 or a PIP signal that is the combined signals from the PC 20 and the TV/video 22, is displayed on the CDT 29.

[0022] While this invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

[0023] As described above, according to the present invention, the PIP function can be realized, and also, a signal of high definition can be displayed on the CDT monitor. 

What is claimed is:
 1. An apparatus for processing a signal, comprising: a signal dispensing unit for dispensing an output signal output from a personal computer in the form of an analog or digital signal; a signal processing unit for performing picture-in-picture signal processing enabling one of a digital personal computer signal generated by the signal dispensing unit and a decoded first signal input from an outside source to be displayed on a main screen and the other to be displayed on at least one sub-screen, and for processing the first signal to be displayed alone on the main screen, the first signal being any one of a television signal and a video signal; an outputting unit for outputting an analog personal computer signal generated from the signal dispensing unit in response to a control signal for displaying only the personal computer signal, and outputting an output signal of the signal processing unit in response to a control signal for displaying the picture-in-picture and first signals; and a monitor for amplifying the signal output from the outputting unit to be displayed.
 2. The apparatus of claim 1, further comprising a signal conversion unit for converting the picture-in-picture signal output from the signal processing unit into an analog signal before a signal is output from the outputting unit.
 3. The apparatus of claim 1, with the signal processing unit, comprising: a decoding unit converting the first signal into a digital signal and decoding the first signal; a scan rate conversion unit for converting a scan rate of the decoded first signal; and a signal processing unit for performing a picture-in-picture signal process on the first signal whose scan rate is converted and the digital personal computer signal, so that one of the first signal and the digital personal computer signal is displayed on the main screen and the other of the first signal and the digital personal computer signal is displayed on the plurality of sub-screens, or for processing the first signal to be displayed alone on the main screen.
 4. The apparatus of claim 1, with the decoded first signal input from an outside source, further comprising: a decoding unit converting the first signal into a digital signal and decoding the first signal; and a scan rate conversion unit for converting a scan rate of the decoded first signal.
 5. The apparatus of claim 2, with the decoded first signal input from an outside source, further comprising: a decoding unit converting the first signal into a digital signal and decoding the first signal; and a scan rate conversion unit for converting a scan rate of the decoded first signal.
 6. A method for processing a signal, comprising the steps of: dispensing an output signal output from a personal computer in the form of an analog or digital signal; performing picture-in-picture signal processing enabling one of a digital personal computer signal generated by the step of dispensing the output signal and a decoded first signal input from an outside source to be displayed on a main screen and the other to be displayed on at least one sub-screen, and for processing the first signal to be displayed alone on the main screen, the first signal being any one of a television signal and a video signal; outputting an analog personal computer signal generated from the step of dispensing an output signal in response to a control signal for displaying only the personal computer signal, and outputting an output signal of the step of performing picture-in-picture signal processing in response to a control signal for displaying the picture-in-picture and first signals; amplifying the signal output from the step of outputting the analog personal computer signal; and displaying the amplified signal output.
 7. The method of claim 6, further comprising the step of converting the picture-in-picture signal output from the step of performing picture-in-picture signal processing into an analog signal before a signal is output from the step of outputting the analog personal computer signal.
 8. The method of claim 6, with the decoded first signal input from an outside source, further comprising: converting the first signal into a digital signal and decoding the first signal; and converting a scan rate of the decoded first signal.
 9. The method of claim 7, with the decoded first signal input from an outside source, further comprising: converting the first signal into a digital signal and decoding the first signal; and converting a scan rate of the decoded first signal.
 10. An apparatus for processing a signal, comprising: a personal computer generating an output signal accommodating a display of an image generated by the personal computer; a signal dispensing unit dispensing the output signal from the personal computer; a signal processing unit performing picture-in-picture signal processing enabling one of the output signal from the personal computer signal generated by the signal dispensing unit and a decoded video signal input from an outside source to be displayed on a main screen and the other to be displayed on at least one sub-screen, and for processing the video signal to be displayed alone on the main screen; an outputting unit outputting the output signal of the personal computer signal generated from the signal dispensing unit in response to a control signal for displaying only the personal computer signal, and outputting an output signal of the signal processing unit in response to a control signal for displaying the picture-in-picture and video signals; and a monitor amplifying and displaying the signal output from the outputting unit.
 11. The apparatus of claim 10, further comprising a signal conversion unit for converting the picture-in-picture signal output from the signal processing unit from a digital signal into an analog signal before a signal is output from the outputting unit.
 12. The apparatus of claim 10, with the decoded video signal input from an outside source, further comprising: a decoding unit converting the video signal into a digital signal and decoding the video signal; and a scan rate conversion unit for converting a scan rate of the decoded video signal.
 13. The apparatus of claim 12, with the decoded video signal input from an outside source, further comprising: a decoding unit converting the video signal into a digital signal and decoding the video signal; and a scan rate conversion unit for converting a scan rate of the decoded video signal.
 14. The apparatus of claim 10, further comprised of the video signal being selected from the group consisting of a television video signal and a non-broadcasted video signal.
 15. The apparatus of claim 10, further comprising: an analog to digital converter unit converting the output signal from the signal dispensing unit from an analog signal into a digital signal for the signal processing unit; and a digital to analog converter unit converting the output signal generated from the signal dispensing unit from a digital signal into an analog signal for the outputting unit. 